14,600 on a 460??

[wigglesworth]

I know it sounds high, but it was still 4-stroking. This is a well broken in machine with a generous muffler mod. I tuned it back to 14,000 in hopes of not blowing it apart. Is anyone running there 460 at this kind of RPM? I searched and the manual says 13,500. By the way it was cutting great, lots of power in the wood, but i did not do any timed cuts or anything. Thanks, Wiggs

 

[Lakeside53]

With what length bar?

 

[wigglesworth]

25" es bar

 

[Lakeside53]

It was likely a little lean then. 14k isn't unreasonable. Do timed cut's if you're concerned.

 

[wigglesworth]

Does anybody else here run at 14k or above? Or I guess a better question is "what is your 460 running?"

 

[GeoffM]

My PS4600 runs at 14,600 which is recommended by Dolmar.

 

[gregz]

13,500 for my ms460

 

[blsnelling]

15,100-15,600. Depending on what I'm doing with it. Of course it's ported

 

[bump_r]

Andy, am I to infer that the factory's rpm spec is for a "stock" machine with "average" bar? That the rotating and reciprocating masses are safe at higher speeds, but the spec rpm is where it typically falls for proper tune?

What I'm getting at - the specified max rpm is a general guide only but tuning by ear and verifying with plug electrode appearence is the final word on where a specific machine's top chain-load rpm should be? That significant deviations are recommended based on chain load (bar length), muffler flow enhancements as well as true hop-ups?

If that's the case, then the high-zoot tach is nothing more than a ballparking device and a trained ear is the true final-word.

 

[blsnelling]

You are exactly right. Factory spec is a ball park number. Nothing replaces fine tuning with timed cuts. I opened up the factory dual port cover on my Dad's early 046 and it's now tuned to 14,500.

 

[bump_r]

huh, I'll be danged. Thanks.

 

[Lakeside53]

Yes... exept that the factory is also concerned with longevity and saftey...

Their number is "about right" with a medium length bar (for the saw in question). A longer bar will have a lower wot for at a correct mixture, and the shorter higher. Stihl's "number" is also +/- 1000 rpm, which means (for Brad..) it's NOT ALWAYS PLUS! Tachs are a good check for the "tune deaf", and a check against the results. They are also useful when setting up wacky igntion limited saws (not all limited systems are "wacky").

 

[bump_r]

Thanks, guys, good stuff.

 

[blsnelling]

Stihl's "number" is also +/- 1000 rpm, which means (for Brad..) it's NOT ALWAYS PLUS!

Who me? Try to tell Tim Allen that. He's my hero!

 

[Scooterbum]

15,100-15,600. Depending on what I'm doing with it. Of course it's ported

Of course

 

[palogger]

my old 046 is running at 16,200 haven't tached my newest one, but id have to guess around, 15,500

 

[wigglesworth]

So am I correct in thinking as long as it is still 4 stroking, and pulling strong, is it in tune?

 

[Lakeside53]

maybe... Do some timed cuts. Best to err on the rich side unless you're showing off at a GTG.

 

[Soilarch]

Are timed cuts the final..final...FINAL word?

(Can we agree on that? Seems like the group here at AS have differing views on the other types/styles of tuning.)

Never wanted/needed to do it before because I look at as "fine tuning". That would be negated the instant the weather changed.

Now if it's the "final word" tuning I may look into it.

Do you allow a smigen of extra time for the chain dulling? (Or is this getting waaaay to OCD?)



Obviously, my chainsaw has never seen a stopwatch!

 

[gink595]

Timed cuts?

I keep seeing this thing about timed cut tuning. I guess I'm still to green, what are you looking for in timed cuts. Obviously the fastest cut but what then? back it off a little?? Is this the most accurate way to get a saw tuned most effiecently for power?